A decline in male sperm quality has been observed over several decades.[11][12][13] Studies on the impact of mobile radiation on male fertility are conflicting, and the effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted by these devices on the reproductive systems are currently under active debate.[14][15][16][17] A 2012 review concluded that "together, the results of these studies have shown that RF-EMR decreases sperm count and motility and increases oxidative stress".[18][19] A 2017 study of 153 men that attended an academic fertility clinic in Boston, Massachusetts found that self-reported mobile phone use was not related to semen quality, and that carrying a mobile phone in the pants pocket was not related to semen quality.[20]
Limit your (and your children’s) cell phone use. This is one of the most obvious ways to limit your exposure to RF waves from cell phones. You may want to use your cell phone only for shorter conversations, or use it only when a conventional phone is not available. Parents who are concerned about their children’s exposure can limit how much time they spend on the phone.
Though some findings were reassuring, others do raise concerns. Specifically, three of the studies—one from Sweden, another from France, and a third that combined data from 13 countries—suggest a connection between heavy cell-phone use and gliomas, tumors that are usually cancerous and often deadly. One of those studies also hinted at a link between cell phones and acoustic neuromas (noncancerous tumors), and two studies hinted at meningiomas, a relatively common but usually not deadly brain tumor.
Wearable tech such as the Apple Watch might as well be called a wearable EMF device. These watches are even worse than mobile phones in that they remain in constant, direct contact with your skin. New York Times columnist Nick Bilton covered this issue in March 2015, noting that constant, low-level radiation from such devices can trigger the formation of cancerous tumors, blood abnormalities, and more.
I don't know why, but I recently had a concern about the fact I keep my smartphone in my pocket for a good part of the day. Was this a "smart" idea, or was there a potential problem with phone radiation? To address this concern, I searched for answers on the Internet. There were a lot of contraptions, many of which seemed to be too good to be true. The one that looked the most promising was Blocsock, not cheap at $24 for the high-end model with the pouch, but it did say it blocked 96% of the cell phone radiation from your body by having special radiation-blocking material on one side, with the side facing away from your body regular material so the phone could still communicate with the outside world. Cheap eBay knockoffs had material on both sides, meaning when you put your phone in them, your phone could't communicate with the outside world! Others did not have the testing results that assured how well the blocking material worked. There is a very detailed SAR test report validating the Blocsock, which I found at sustainablemobile.com. You can Google it. It is a very exhaustive testing report!
The following charts list SAR levels for the Apple iPhone, Samsung Galaxy S, as well as 20 of the highest SAR level cellphones and 20 of the lowest SAR level cellphones. The list provides the maximum possible SAR level from the phone (many phones have differing SAR levels depending on where and how the phone is used). If your phone is not on either list, you can find the SAR level for your specific phone by checking the online FCC database.

Don’t rely on a “radiation shield” or other products claiming to block RF energy, electromagnetic fields, or radiation from cell phones. According to the U.S. Federal Trade Commission, products that interfere with the phone’s signal may force it to work harder and emit more RF energy in order to stay connected, possibly increasing your exposure. It is best to use wired solutions to reduce RF rather than rely on an untested product.

Searching PubMed for studies published in the past 10 years, we found 102 studies that ultimately resulted in 12 relevant systematic reviews. To limit bias in our assessment of the literature, we used a validated critical appraisal tool called AMSTAR to determine the quality of each review. Eight of the reviews were critically low quality, two were low quality, and two were moderate quality.
Researchers have carried out several types of epidemiologic studies in humans to investigate the possibility of a relationship between cell phone use and the risk of malignant (cancerous) brain tumors, such as gliomas, as well as benign (noncancerous) tumors, such as acoustic neuroma (tumors in the cells of the nerve responsible for hearing that are also known as vestibular schwannomas), meningiomas (usually benign tumors in the membranes that cover and protect the brain and spinal cord), and parotid gland tumors (tumors in the salivary glands) (3).